Device for secondary electric clocks



(No Model.) 2 Sheets-Sheet 1.

A. S. CRANE.

ACTUATING DEVICE FOR SECONDARY ELECTRIC CLOCKS.

No. 288,623. Patented Nov. 20, 1883.

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WITNESSES.

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(No Model.) 2 Sheets-Sheet 2.

s. CRANE.

AOTUATING DEVICE FOR SECONDARY ELEGTRIG CLOCKS.

No. 288,623. Patented Nov. 20, 1883.

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AUGUSTUS S. CRANE, OF NEXVARK, NEV JERSEY.

ACTUATING DEVICE FOR SECONDARY ELECTRIC CLOCKS.

SPECIFICATION forming part of Letters Patent No. 288,623, dated November 20, 1883.

Application filed May 9, 1883. (No model.)

To aZZ whom it may concern:

Be it known that I, AUeUsTUs S. CRANE, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain Improvements in Electric Clocks, of which the following is a specification.

My invention relates, principally, to secondary electric clocks, or those which are driven by an electro-magnet arranged in a circuit which is controlled by a circuit-breaking primary clock, but it is in part applicable to primary clocks, or, indeed, to any analogous apparatus where the successive excitations of one or more electro-magnets are desired to intermittently advance an indicating mechanism.

Figure 1 of the accompanying drawings is a rear elevation of the movement of a secondary electric clock constructed according to the preferred form of my invention. Fig. 2 is a side elevation of the same. Fig. 3 is a fragmentary detail View on a larger scale. Fig. 4. illustrates a modification. Fig. 5shows a further modification, illustrating the application of my invention to a primary electric clock. Fig. 6 is an enlarged fragmentary view, illustrating another modification, and Fig. 7 is a side view thereof, partially in section.

I will first describe my invention in its application to secondary electric clocks, as illustratcd in Figs. 1, 2, and 3.

Let A designate the frame of the cloclc movement; a, the minute-arbor; Z), the tubular hour-arbor; c, the pinion on a,- d, the gear on Z); and candf, the dial-wheels gearing with c and d, for communicating a reduced motion to the hour-arbor I). These parts are or may be all of the usual construction.

On the arbor a is fixed a wheel, B, having sixty radial teeth, g g, on its periphery, equally spaced, forming thereby sixty intervening notches or sockets, h h.

C is an anchor which is fixed to and vibrates with the armature D of an electro-inagnet, E, and bears two pallets, 'i i, which are fastened to or formed on it at or near its upper end. These pallets are of peculiar form, as best shown in Fig. 3. Each has an inclined propelling-face, j, and two opposite parallel faces, k 7:. lVhile the mechanism is at rest one or other of the pallets is in engagement with the wheel 13, being inserted into one of its notches 71 with its parallel faces 7c 7 in contact with the two adjoining teeth y g. As the faces k k of the pallet are approximately at right angles to the direction of motion of the teeth 9 g, and approximately parallel with the direction of motion of the pallets, the wheel B cannot be turned or displaced until the pallet is withdrawn. Thus a pallet of my construction constitutes a locking-pallet which effectually prevents any accidental displacement of the wheel, and greatly reduces the liability of its being tampered with. Upon the vibration ofthe anchor Oto the opposite side the pallet which has been holding the wheel passes out and frees itself, and simultaneously the opposite pallet engages one of theteeth f], between which the first pallet has been standing, and its inclined face j forces this tooth upward until it passes above that face, whereupon the pallet passes between this tooth and the one below, and the wheel is again locked by the faces k 70. The motion of the pallets and a11- chor in each direction is limited by shoulders H, "which strike the teeth g, or it may be limited by suitable stops elsewhere arranged; but there must be sufficient motion to cause the faces k 7. to enter between the teeth 9 The armature is retracted by a spring, m. Its fulcrum-pivots n a are arranged at its ends, so that its pivotal axis traverses it longitudinally along one side or edge, somewhat close to the cores of the magnet. This arrangement admits of bringing the entire armature down over the poles of the magnet, where the attractive power is great,-the magnet being necessarily arranged fiatwise against the frame A, as shown, for the sake of compactness. This arrangement of the armature is made possible by constructing the anchor to work across the edge of the toothed wheel, instead of in the same plane as the wheel. The latter arrangement is that heretofore used in propelling-escapements, as exemplified in my ap plication for patent filed January 26, 1883, where the two pallets are on diametrically-opposite sides of the wheel, and work alternately toward and from its axis. Even if the pallets in my present construction had no locking faces, they would still possess this ad vantage of permitting a more effective ar rangement of the armature, and also the additional important advantage that less accuracy would be necessary in cutting the teeth of the wheel B, as both pallets engage the teeth on the same side of the wheel, so that aslight error in spacing will not affect the operation. In the construction above referred to, however, where the pallets span the wheel and engage it upon diametrically-opposite sides, any error in spacing is doubled in its efi'ect on the operation, so that the successive advancesof the wheel exhibit twice the irregularity that there is in the spacing of the teeth.

A secondary clock, constructed as already described with reference to Figs. 1, 2, and 3,

' being arranged behind a dial and fitted with hour and minute hands, is operated by closing and breaking the line-circuit once each minute, either by leaving the circuit closed for but an instant, in which case the minute-hand will advance a minute on the dial in two quick successive movements, orby closing the circuit once each minute and leaving it closed during thirty seconds, in which case the minute-hand will advance a half-space each halfminute. For the former method it might answer if only one of the pallets werea locking-pallet, the one which acts upon the closure of the circuit having only the inclined face j.

Fig. 4 shows a different arrangement of magnet and armature and a different construction of wheel B. As the anchor, thus arranged, plays across the'face instead of across the edge of the wheel, it is necessary that the teeth 9 shall project perpendicularly from the face of the wheel. For this purposethe teeth may be formed by short round pins or studs, set in the wheel, as shown, or they may be formed as in Fig. 1, and bent at right angles.

Instead of teeth, holes may be used, as shown in Figs. 6 and 7, where-h h denote round holes punched or drilled through the wheel B, and corresponding to the notches or spaces h h in Figs. 1 and 3, while theinterveningportions of metal answer to the teeth 9 g. The pallets i i arehere made of round wire or rod having beveled ends.

Fig. 5 illustrates the application of my present invention tothe form of primary electric clock shown in my application for patent filed January 26, 1883, in lieu of the device shown in Fig. 6 thereof. E and E are the-two oppositely acting electro -magnets, and the toothed wheel B is mounted on theseconds-arbor and has thirty teeth. At the end of each second the current is shunted out of one magnet and into the other, thereby rocking the lever F, vibrating the anchor O to the opposite side, and turning the wheel B one-sixtieth of a revolution.

It is evident that instead of mounting a clock-hand on the arbor a, a disk or drum having figures, words, or other characters on its surface or periphery might be mounted upon it or driven from it in such manner as to expose one character at a time-through an opening in a screen. In such case the wheel B might have any required number of teeth other than sixty or thirty.

I am well aware that pendulum-clocks have been provided with escapements somewhat resembling my present invention, in that the pallets have had parallel faces which, if they entered between the teeth on the scape-wheel and remained there, might serve as lookingpallets in the same sense as mine. Butin all such clocks the vibration of the anchor has been too limited to permit these parallel faces to enter between the teeth; and, moreover, in apendulum-clock there is no occasion for looking the wheel, since the impulse of the spring keeps the latter in place against the pallets, and, indeed, causes it to communicate motion to the anchor and pendulum.

I am aware, also, of an electric pendulumclock wherein the pendulum is kept swinging by an electromagnetic impulse, and is connected to an anchor which it vibrates, and so propels a toothed wheel; but in this clock the pallets enter between the teeth on the wheel only far enough to. propel the wheel the requisite distance, and not far enough to interpose locking-faces; nor would it be desirable to do so in a clock of that character, as the pallet no sooner enters the teeth than it recedes. My invention is especially designed vfor clocks wherein there is a rest between the impulses of suflicient duration to create a liability that the wheel may become displaced sufficiently to derange the operation.

I claim as my invention 1. As ameans for operating an electric clock or other analogous device, the combination, with a wheel having circumferential teeth or sockets, of avibrating anchor bearing opposed pallets which are formed with inclined propelling-faces, and arranged both on one side of the axis of rotation of the wheel, whereby, when the anchor is vibrated, they alternately engage adjoining or adjacent teeth or sockets for the purpose and to the eifect specified, and an electro-magnet connected to and adapted to vibrate said anchor, substantially as set forth,whereby, when said anchor is vibrated in either direction by said magnet, one of said pallets enters a socket or space between two teeth on said wheel, and advances the wheel the distance from one tooth or space to the next.

2. In an electric clock or analogous device, the combination, with a wheel having circumferential teeth or sockets, of a vibrating anchor bearing opposed pallets which are formed with inclined propelling-faces, and one or both of which are formed with locking-faces extending substantially parallel to each other and to the direction of motionof the pallets, and means for vibrating said anchor, all'combined and adapted to operate substantially as set forth, whereby whenever the anchor is vibrated in either direction, one of the pallets enters-between two ,teeth on the wheel and IIO propels the latter forward the distance from one tooth to the next, and continues its movement until its parallel locking-faces enter between the two teeth, whereby the wheel is locked or fastened in position until the neXt vibration of the anchor.

3. In an electric clock or other analogous device, the combination of wheel B, having circumferential teeth or sockets, with anchor O, pallets i t thereon, formed with inclined pro pelling-face j, and one or both formed with opposite parallel locking-faces k k, extending substantially parallel with the direction of motion of the pallets, and approximately at right angles to the direction of motion of the teeth on the wheel B, and electro-magnet E, the movable portion or armature of which is connected to said anchor and constructed to vibrate the same to asuflicient extent to cause the locking-faces on either pallet to enter between two teeth on the wheel, substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

AUGUSTUS S. CRANE.

XVitnesses ARTHUR O. FRASER, GEO. BAIXTON, 

